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T O P I C R E V I E W

Robert Pearlman

Ben Cooper embarked on a risky 24-hour shot at photographing the only total solar eclipse for 2013, hoping to intercept seven seconds of the moon's shadow over the Central Atlantic from a Falcon 900B jet.

Unlike most eclipse flights, this one has no margin for error, and we must intercept the right spot at the right moment, flying perpendicular to the shadow as it begins its race across the ocean at nearly 4 km/s. If successful, it would be a first.

As seen from 42,000 feet over the Central Atlantic, some 600 miles southeast of the island of Bermuda, the sun puts on a near instantaneous show of totality. Our plane, intercepting in a manner never done before, was about one second off for central totality. Some telephoto shots suffered from turbulence.

Unlike most eclipse flights, this one has no margin for error, and we must intercept the right spot at the right moment, flying perpendicular to the shadow as it begins its race across the ocean at nearly 4 km/s. If successful, it would be a first.

First time I heard of this type of eclipse chase maneuver was after the total solar eclipse of October 3, 1986. Glen Schneider told me about writing software for catching an even shorter eclipse — one second duration — from Iceland aboard a Cessna Citation II jet.

Not only was the eclipse short, but the low altitude (some would call it elevation) of the sun meant that the ground track of the sub-airplane point was miles from the ground track for central path of the moon's shadow. They did it all without the benefit of GPS! And with technology that existed 27 years prior to the current eclipse. I found a summary of this mission, linked below:

In the meantime, here in Maryland, we saw an approx. 35% covered sun at sunrise yesterday, with the partial eclipse lasting for 30 minutes. It was a spectacular sunrise.

Ben

That's right, and Glenn helped with tips for our flight. But with the 1986 flight, like most, the airplane followed the path and waited for the shadow to catch up. For yesterday's intercept, a first, this was not possible unless only the pilots were to see it. So we had to cross the shadow at 90 degrees and thus intercept a specific spot at the right instant. Yes, GPS and modern day technology played the biggest role!

cspg

The picture is today's Astronomy Picture of the Day (APOD, November 7). Congratulations!